Python 3.2.3 (default, Apr 11 2012, 07:15:24) [MSC v.1500 32 bit (Intel)] on win32
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<MICHAL: value can have names or not. Here the parameter 2**10 is computed in memory but there is no name referring to it>

>>> print(2**10)
1024

<MICHAL: The same example but this time the value has a name>

>>> x = 2**10
>>> print(x)
1024


<MICHAL: In Python functions can also have names or not. Here is an example of an anonymous function using lambda expressions>

>>> (lambda x:x+2)
<function <lambda> at 0x00B59150>


<MICHAL: calling an anonymous function>

>>> (lambda x:x+2)(6)
8


<MICHAL: Another way of writing a "named" function>

>>> plus2 = lambda x:x+2
>>> plus2(6)
8


<MICHAL: Example 1 of using lambda expressions: writing a function returning a function>


>>> def make_pow(n):
	return lambda x:pow(x,n)

>>> sqr = make_pow(2)
>>> type(sqr)
<class 'function'>
>>> sqr(3)
9
>>> cub = make_pow(3)
>>> cub(2)
8

<MICHAL: We could have written the same function but without lambda expressions...>


>>> def make_pow(n):
	def fixed_exponential_pow(x):
		return pow(x,n)
	return fixed_exponential_pow

>>> sqr = make_pow(2)
>>> sqr(4)
16





<MICHAL: Example 2 of using lambda expressions: a function that gets a function as a parameter>




<MICHAL: Sorted returns a new sorted list with the items of the original list. Sorts according to the items in the list. For instance: string s are compared lexicographically>

>>> l = ["michal","amir","daniel","amiram"]
>>> l
['michal', 'amir', 'daniel', 'amiram']
>>> sorted(l)
['amir', 'amiram', 'daniel', 'michal']

<MICHAL: we can define a function that given a list item returns the key according to which this items are compared
	 In the next example the items are sorted according to the item length>

>>> sorted (l, key=lambda s:len(s))
['amir', 'michal', 'daniel', 'amiram']

<MICHAL: In the next example the items are sorted according to the lexicographic order of the reversed strings>

>>> sorted(l, key=lambda s:s[::-1])
['michal', 'daniel', 'amiram', 'amir']

<MICHAL: In the next example the items are sorted according to the int value of the strings>

>>> l1 = ["1111","2","33"]
>>> sorted(l1,key=int)
['2', '33', '1111']



<MICHAL: Example 3 of using lambda expressions: a function that both gets and returns a function as a parameter>


<MICHAL: definition without lambda>

>>> def compose(f1,f2):
	def com(x):
		return f1(f2(x))
	return com

>>> h1 = compose(lambda x:x+1, lambda x:2*x)
>>> h1(5)
11
>>> h1 = compose(lambda x:2*x,lambda x:x+1)
>>> h1(5)
12

<MICHAL: definition with lambda>

>>> def compose(f1,f2):
	return lambda x:f1(f2(x))

>>> h1 = compose(lambda x:x+1, lambda x:2*x)
>>> h1(5)
11

>>> def plus1(x):
	return x+1

>>> h1 = compose(plus1, lambda x:2*x)
>>> 


<MICHAL: Example 4 can be found in r08_lambda.py file>